Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002736 (amyotrophic lateral sclerosis)
 19,048 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Motor fatigue is a common complaint in patients with amyotrophic lateral sclerosis (ALS), but is often excluded, unlike weakness, from the clinical assessment of these patients. This could be due to the complexity and often painful assessment techniques of this motor deficit. This study examines the feasibility of quantitative assessment of motor fatigue by modifying presently available force measurements. The relationship between weakness and fatigue in ALS patients was also examined. Fifty-four ALS patients and 39 normal control subjects performed 30 s of sustained maximal voluntary isometric contraction (MVIC) of elbow flexors (EF), knee extensors (NE), and ankle dorsiflexors (DF), using a computerized force measurement system and standardized testing procedures. Fatigue index (FI) was digitally calculated, from the force-time curve, as the percentage of MVIC unable to be sustained over the 30-s period. Fatigue was greater in ALS patients than in normal control (mean=23% vs. 15%) in all muscles including muscles that were not clearly weak. Weakness and fatigue were poorly correlated in ALS patients and may be independent measures of the pathogeneses of ALS.
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PMID:Quantitative assessment of motor fatigue in amyotrophic lateral sclerosis. 1167 92

Within the framework of an early drug access programme launched in 1995, a multicentre open study was initiated in France in order to assess, inter alia, the safety of riluzole (50 mg twice a day) in a total of 2069 patients from 28 centres. This programme, a phase IIIb study with direct individual benefit, had two main objectives: to enable patients to receive riluzole therapy pending regulatory approval and commercial availability and to provide further data on the safety of riluzole in a broader ALS population. The most frequent adverse events related to riluzole treatment were: asthenia, nausea and elevation of serum transaminase levels. These observations, similar to data derived from previous pivotal clinical trials, confirm that riluzole has a satisfactory tolerability profile.
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PMID:[Tolerance of riluzole in a phase IIIb clinical trial]. 1209 Jan 50

Riluzole is a neuroprotective drug that modulates glutamergic transmission but also blocks the inactivated state of voltage-gated neuronal sodium channels at very low concentrations (about 0.1 microM). After nausea, the most common adverse effect of riluzole is asthenia, which could be due to a block of muscle sodium channels or acetylcholine receptor channels. Using the patch-clamp technique, we applied riluzole on recombinant voltage-gated skeletal muscle sodium and adult nicotinic acetylcholine receptor channels expressed in a mammalian cell line (HEK 293). Riluzole blocked the inactivated state of voltage-gated skeletal muscle sodium channels, shifting the midpoint of the steady-state inactivation curve to more negative potentials, but only in comparatively high concentrations (> or = 0.1 mM). At these concentrations, riluzole also caused an open-channel block at acetylcholine receptor channels. We conclude that riluzole has only a mild blocking effect on the inactivated state of voltage-gated skeletal muscle sodium channels and nicotinic acetylcholine receptor channels. As the plasma concentration of riluzole in amyotrophic lateral sclerosis (ALS) patients approximates 2 microM, it seems unlikely that asthenia is caused by a block of skeletal muscle sodium channels or acetylcholine receptor channels by riluzole.
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PMID:Interaction of high concentrations of riluzole with recombinant skeletal muscle sodium channels and adult-type nicotinic receptor channels. 1236 21

We report the clinical and laboratory findings in the largest kindred so far recorded with familial amyotrophic lateral sclerosis due to an A4T mutation in the SOD1 gene. The age of onset ranged from 32 to 60 years, with a mean of 46 years. Weakness in the legs was the most frequent early symptom and there was a predominance of lower motor neuron signs. The mean time from onset of symptoms to death was 14 months. One man with onset at the age of 37 has shown a slowly developing form and is currently alive 76 months after diagnosis (October 2002), although severely affected. The A4T mutation, with one exception, was of similar severity to the A4V mutation.
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PMID:A4T mutation in the SOD1 gene causing familial amyotrophic lateral sclerosis. 1279 43

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease with the fatal evolution. Recent studies in knowledge of the pathogenic mechanisms underlying ALS showed that the excitotoxicity has an important role in the neurodegeneration. The riluzole, an antagonist of glutamate, is the first drug approved by FDA for the treatment of patients with ALS. The efficacy of riluzole (dose recommended 50 mg twice a day) in prolonging the survival of patients with ALS has been demostrated in two principal controlled clinical trials. The most frequent adverse events related to riluzole treatment were: nausea, vomiting, anorexia, diarrhea, asthenia, somnolence, vertigo, circumoral paresthesia, abdominal pain and dizziness. Some events tend to be related to the dose: vertigo, diarrhea, nausea, circumoral paresthesia and anorexia appear more frequently with 200 mg/die that with lower dose. Generally with tree months from the beginning of the treatment with riluzole, an increase serum transaminase levels has been noted; mostly transient and regressing after two-sex months of treatment. A monitoring of serum transaminase levels is suggested during the first year of treatment with riluzole The clinical studies shows that the adverse events produced by riluzole are mostly reversible and dose-dependent, this demostrates a satifying profile of tolerability of the drug. Anyway, a deeper knowledge of its tolerability may lead us to a better use of riluzole, avoiding in this way the interruption of treatment.
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PMID:[Tolerability of riluzole: a review of the literature]. 1514 78

Riluzole is the only disease-modifying drug approved for the treatment of amyotrophic lateral sclerosis (ALS), in which it has been demonstrated to extend survival. The overall tolerability of riluzole is good and the drug can be used in all patients with ALS except those with elevated transaminase levels or active liver disease. The most frequently encountered adverse events (AEs) that appear to be attributed to riluzole are asthenia and nausea, observed in 18 and 15% of patients taking riluzole in the randomised clinical trial programme, respectively. These same AEs, albeit at a lower frequency, are also reported in Phase IV observational studies and in pharmacovigilance surveys. No unexpected AE clearly related to riluzole has emerged in the seven years that riluzole has been in extensive use in ALS patients. The most important potential safety issue with riluzole is hepatic impact with elevations of transaminases. Serum alanine aminotransferase levels more than three times the upper limit of normal are observed in 10 - 15% of patients. For this reason, strict monitoring of liver enzymes is recommended in patients with ALS taking riluzole, and treatment is contraindicated in subjects with elevated transaminases before the start of treatment. There is a suspicion that riluzole may, in rare cases, cause neutropenia, and physicians should be vigilant towards this risk.
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PMID:The tolerability of riluzole in the treatment of patients with amyotrophic lateral sclerosis. 1550 Apr 12

Evidence of upper motor neuron (UMN) dysfunction is essential in making the diagnosis of amyotrophic lateral sclerosis (ALS). Central motor conduction (CMC) abnormalities detected using transcranial magnetic stimulation (TMS) are presumed to reflect UMN dysfunction. CMC is, however, often normal in patients with classical sporadic ALS. The aim of the study was to determine whether the utility of the CMC measure in ALS could be enhanced. We measured CMC to four pairs of muscles (abductor digiti minimi (ADM), biceps, vastus medialis (VM) and abductor hallucis (AH) in 20 controls and 25 ALS patients. The commonest abnormality detected in the ALS patients was an absent MEP, found in 11 patients (44 %) and in 25 of 200 muscles examined. Studying a minimum of three muscles increased the probability of detecting UMN dysfunction. Weakness in the muscle as well as selecting a distal rather than a proximal muscle was significantly associated with an abnormal CMC. Interside differences in CMC were significantly more pronounced in the patient group. In 30% of patients a significant interside difference in AH CMC time was the sole abnormality, suggesting mild UMN dysfunction on the side with the longer CMC.
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PMID:Optimising the detection of upper motor neuron function dysfunction in amyotrophic lateral sclerosis--a transcranial magnetic stimulation study. 1559 32

We hypothesize that a yet-to-be-identified motor neuron toxin produced by a clostridial species causes sporadic amyotrophic lateral sclerosis (ALS) in susceptible individuals. This clostridial species would reside undetected in the gut and chronically produce a toxin that targets the motor system, like the tetanus and botulinum toxins. After gaining access to the lower motor neuron, the toxin would be transported back to the cell body, as occurs with the tetanus toxin, and destroy the lower motor neuron - the essential feature of ALS. Again like the tetanus toxin, some of the toxin would cross to neighboring cells and to the upper motor neuron and similarly destroy these motor neurons. Weakness would relentlessly progress until not enough motor neurons remained to sustain life. If this hypothesis were correct, treatment with appropriate antibiotics or antitoxins might slow or halt progression of disease, and immunization might prevent disease.
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PMID:Hypothesis: a motor neuron toxin produced by a clostridial species residing in gut causes ALS. 1623 60

Weakness is a characteristic of muscles influenced by the postpolio syndrome (PPS), amyotrophic lateral sclerosis (ALS), and spinal cord injury (SCI). The strength deficits relate to changes in muscle use and to the chronic denervation that can follow the spinal motoneuron death common to these disorders. PPS, ALS, and SCI also involve variable amounts of supraspinal neuron death, the effects of which on muscle weakness remains unclear. Nevertheless, weakness of muscle itself defines the functional consequences of these disorders. A weaker muscle requires an individual to work that muscle at higher than usual intensities relative to its maximal capacity, inducing progressive fatigue and an increased sense of effort. Little evidence is available to suggest that the fatigue commonly experienced by individuals with these disorders relates to an increase in the intrinsic fatigability of the muscle fibers. The only exception is when SCI induces chronic muscle paralysis. To reduce long-term functional deficits in these disorders, studies must identify the signaling pathways that influence neuron survival and determine the factors that encourage and limit sprouting of motor axons. This may ensure that a greater proportion of the fibers in each muscle remain innervated and available for use.
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PMID:Fatigue of muscles weakened by death of motoneurons. 1602 25

Weakness of the neck extensors can lead to "dropped head syndrome", a condition of progressive cervical kyphosis in which a patient is unable to hold their head up against the force of gravity. This condition can be associated with structural abnormalities of the spine as found in ankylosing spondylitis and vertebral fractures. Neuromuscular disorders, such as myasthenia gravis, muscular dystrophies, inflammatory myopathies, and motor neuron disorders such as amyotrophic lateral sclerosis (ALS) have also been reported as etiologies of dropped head syndrome. In this article, we describe an elderly woman with rapidly progressive cervical kyphosis following an injection of botulinum toxin A into her neck extensor musculature.
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PMID:Progressive cervical kyphosis associated with botulinum toxin injection. 1692 88


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